Nozzle devices have one main use in fire extinguishing work. To achieve the safety of workers involved in fire extinguishing work, single-hole nozzles, which are suitable for spraying water to distant places, have been used in the fire extinguishing work. A single-hole nozzle can spray water with high compression at its destination and with strong destructive power, and can be used to extinguish fires while displacing obstacles. However, the single-hole nozzle cannot spray water in a wide spray pattern. When the area for extinguishing fires is wide, the orientation of the fire extinguishing nozzle is to be changed as appropriate in the fire extinguishing work. This places a large burden on workers who perform the fire extinguishing work, and extends the time taken to extinguish fires.
Multi-hole nozzles including a plurality of nozzles arranged at different angles have been developed to spray fluids, such as water, to distant places in wide spray patterns.
Japanese Unexamined Patent Application Publication No. 2009-291699 (Patent Literature 1) describes a nozzle device for extinguishing fires including a plurality of nozzle cases. The nozzle device for extinguishing fires described in Patent Literature 1 includes a central nozzle case and a plurality of nozzle cases surrounding the central nozzle case. The surrounding nozzle cases are tilted away from the center nozzle case toward their tips. This nozzle device can easily spray water to a wider area than a single-hole nozzle.
However, the nozzle device for extinguishing fires described in Patent Literature 1 includes the surrounding nozzle cases that are fixed on a nozzle mounting base at fixed spraying angles, and thus cannot change the size of an area into which water is sprayed without changing the positioning for the fire extinguishing work. This has increased the need for multi-hole nozzles that can change their spraying angles.
Japanese Unexamined Patent Application Publication No. 2012-135460 (Patent Literature 2) describes a water-spraying nozzle device for extinguishing fires that can change the tilt angles of the surrounding nozzles included in the multi-hole nozzle (refer to FIG. 5 in Patent Literature 2).
The water-spraying nozzle device for extinguishing fires described in Patent Literature 2 includes a plurality of surrounding nozzles each with a two-part structure including a stationary branch pipe arranged at an angle such that these surrounding nozzles are oriented away from one another toward the spraying side, a movable water spraying pipe, and a joint fitting that joins the movable pipe to a distal end of the stationary branch pipe in a rotatable manner. The tilt angles of the movable water spraying pipes are changed by axially moving angle adjusting shafts, which externally support the movable water spraying pipes, in cooperation with rotation of a ring part included in an angle adjusting mechanism to axially change the positions at which the angle adjusting shafts support the movable water spraying pipes.